Apparatus and method for partitioning moving picture data

ABSTRACT

An apparatus for partitioning moving picture data comprises a first quantizing unit for first-quantizing a received video signal and outputting a first-quantized signal; and a second quantizing unit for second-quantizing the first-quantized signal and partitioning the first-quantized signal into a preceding part and a succeeding part.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 119(a), this application claims the benefit ofearlier filing date and right of priority to Korean Patent ApplicationNo. 2003-14095, filed on Mar. 6, 2003, the content of which is herebyincorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus and a method forpartitioning moving picture data and, in particular, to an apparatus anda method for partitioning DCT coefficient information in order toperform error tolerance transmission of moving picture information.

2. Description of the Background Art

According to popularization of digital image services such as a digitalTV broadcast including a high definition TV, a digital versatile disc(DVD) is attracting public attention as a new multimedia device. MPEG(moving picture experts group) is the international standard fordefining streaming video and audio over a communication network. It isregulated by the ISO/IEC (international electrotechnical commission) ofthe ISO (international standard organization). Standardization of MPEGhas proceeded with the cooperation of the internationaltelecommunication union (ITU).

The MPEG standard partly concerns coding video and audio informationstored in a digital storage medium. However, at present its applicationis expanded to multimedia database access or radio multimediacommunication. In particular, MPEG-2 has been developed as a multimediastandard for next generation broadcast, such as a HDTV and a digitalsatellite broadcast. Presently MPEG-4 is a multimedia coding method, andit is a kind of system protocol for defining interface with acommunication network.

FIG. 1 is a block diagram illustrating a construction of an encoder usedfor a data partitioning method in accordance with the related art. Asdepicted in FIG. 1, the encoder includes a first combining unit 1 foradding a received video signal to a compensated signal; a DCT unit 2 forperforming DCT (discrete cosine transform) of a signal outputted fromthe first combining unit 1; a quantizing unit 3 for quantizing a signalof the DCT unit 2; an inverse-quantizing unit 4 for inverse-quantizing asignal outputted from the quantizing unit 3; and an IDCT (inversediscrete cosine transform) unit 5 for performing IDCT of a signaloutputted from the inverses-quantizing unit 4.

Also included are a second combining unit 6 for combining an outputsignal of the IDCT unit 5 with an output signal of a motion compensatingunit 9; a frame memory 7 for clipping and storing a signal outputtedfrom the second combining unit 6; a motion judging unit 8 for estimatingmotion through a signal of the frame memory 7 and a received videosignal; a motion compensating unit 9 for compensating motion byreflecting the estimation judged in the motion judging unit 8 in thesignal stored in the frame memory 7; and a data partitioning unit 10 forreceiving a result judged in the motion judging unit 8 and the signal ofthe quantizing unit 3 and outputting data-partitioned streams.

The data partitioning method is a technique for partitioning a videostream into not less than two parts. The data partitioning method usedfor encoding standardization is for separating motion information andmetro block header from a DCT coefficient. In video stream transmission,if part of texture information consisting of the DCT coefficient islost, the texture information is disregarded, and accordinglyreproduction screen is constructed only with motion information.However, in an encoding frame in a screen, because there is no motioninformation, the DCT coefficient loss has a bad effect upon a picturequality of a moving picture.

In order to reduce an error due to the DCT coefficient loss, a spectrumseparation method for separating the DCT coefficient into two parts hasbeen presented. In the DCT coefficient, visually important low frequencycomponents are allocated to a priority part, and the rest of highfrequency components are allocated to a background (lower priority)part.

FIG. 2 shows a bit string structure of the data partitioning method usedfor the MPEG-2 standard, and arrows (A, B, C, D) indicate decodingorders. In the MPEG-2 standard, the DCT coefficient is divided into apartition 0 corresponding to a priority part and a partition 1corresponding to a background (lower priority) part, construction partincluded in the partition 0 is determined by a priority breakpoint. Inmore detail, by the priority breakpoint value, it is determined whetherhow many coefficients are included in the priority part (partition 0),and the rest low frequency parts are included in the background part.

The spectrum separation method can provide error immunity about the DCTcoefficient, however, picture quality of the priority part isconsiderably lowered in comparison with a single stream having the samebit rate. Accordingly, when error occurs in the background part,although screen is constructed only with the priority part, there is notsuch a big gain.

FIGS. 3A and 3B show a bit string structure of the data partitioningmethod used for the MPEG-4 standard. Herein, FIG. 3A shows framesbetween screens, and FIG. 3B shows frames in a screen. In frames betweenscreens, a macro block header and motion information are separated fromthe DCT coefficient and are allocated to the priority part, and the DCTcoefficients is allocated to the background part. In frames in a screen,only a DC coefficient is allocated to the priority part with a macroblock header, and the rest AC coefficient is allocated to the backgroundpart.

In general, when an error occurs in the background part, an encoder hasto reconstruct a screen by using the priority part information. In moredetail, if the DCT coefficient of the frames between the screens is lostdue to a transmission error, the encoder reconstructs the damaged macroblock with motion information. If the background part of the frame inthe screen is lost due to an error, the encoder has to reconstruct themacro block only with the DC coefficient. In addition, if an erroroccurs in the priority part, the encoder has to disregard the encodedall information.

In the current method for partitioning moving picture data, the spectrumseparation method does not include all frequencies in the priority part.Therefore, picture quality in the priority part is remarkably lowered incomparison with a single stream having the same bit rate. In moredetail, due to error occurred in the background part, a picturequality-lowering problem occurs seriously in reproducing of the screenonly with the priority part. A system and method is needed that canovercome the above shortcoming.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problem, it is an object of thepresent invention to provide an apparatus and a method for partitioningmoving picture data capable of partitioning a DCT coefficientefficiently by performing re-quantization in the conventional datapartitioning method.

In accordance with one or more embodiments, an apparatus forpartitioning moving picture data comprises a first quantizing unit forfirst-quantizing a received video signal and outputting afirst-quantized signal; and a second quantizing unit forsecond-quantizing the first-quantized signal and partitioning thefirst-quantized signal into a preceding part and a succeeding part.

The second quantizing unit comprises a second quantizer forre-quantizing the first-quantized signal to generate an output signal; afirst variable length coder (VLC) for variable-length coding the outputsignal generated by the second quantizer; a second inverse-quantizer forinverse-quantizing the output signal generated by the second quantizer;a third combiner for performing subtraction operation of output signalsgenerated by a first inverse-quantizer and the second quantizer; asecond VLC for variable-length coding output signals generated by thethird combiner and the second quantizer; and a data partitioner foroutputting output signals generated by the second VLC and the first VLC.

The preceding part and the succeeding part comprise at least onefrequency component. The second quantizer outputs an even-approximatedcoefficient as the preceding part by having a quantization interval setto a predetermined value. An output signal of the third combiner is anodd-remainder coefficient as the succeeding part equal to apredetermined value. The odd-remainder coefficient comprises codeinformation when the odd-remainder coefficient is equal to a first valueand a pertinent even-approximated coefficient is not equal to a secondvalue.

The first value is approximately 1; the second value is approximately 0,in accordance with one embodiment. Preferably, the odd-remaindercoefficient as the succeeding part is equal to approximately 0; theodd-remainder coefficient as the succeeding part is equal toapproximately 1, for example.

An apparatus for partitioning moving picture data comprises a codingunit for outputting a stream comprising a DCT coefficient divided intoan even-approximated coefficient and an odd-remainder coefficient byfirst-quantizing and second-quantizing a received video signal; and adecoding unit for obtaining a first-quantized signal by performinginverse-quantization about the stream generated by the coding unit andobtaining a restored video signal by performing inverse-quantizationabout the first-quantizing.

The coding unit comprises a first quantizer for outputting afirst-quantized signal by first-quantizing a received video signal; asecond quantizer for outputting an even-approximated coefficient byre-quantizing the first-quantized signal; a first VLC (variable lengthcoder) for variable-length coding an output signal of the secondquantizer; a second inverse-quantizer for inverse-quantizing an outputsignal of the second quantizer; a third combiner for outputting anodd-remainder coefficient by performing subtraction operation of outputsignals of the second inverse-quantizer and the first quantizer; asecond VLC (variable length coder) for variable-length coding outputsignals of the third combiner and the second quantizer; and a datapartitioner for outputting output signals of the second VLC and thefirst VLC as a data-partitioned stream.

An output signal of the third combiner is an odd-remainder coefficient.The odd-remainder coefficient comprises code information when it isequal to a first value and a pertinent even-approximated coefficient isnot equal to a second value. The decoding unit comprises a divider fordividing the data-partitioned stream into a preceding part and asucceeding part; a first VLD (variable length decoder) for outputting aneven-approximated coefficient by variable-length decoding the precedingpart; a first inverse-quantizer for inverse-quantizing an output signalof the first VLD; a second VLD (variable length decoder) forvariable-length decoding the succeeding part; a first combiner foroutputting a first-quantized signal by combining an output signal of thefirst inverse-quantizer with an output signal of the second VLD; and asecond inverse-quantizer for outputting a video signal by performinginverse-quantization and inverse discrete cosine transform of the firstquantized signal.

A method for partitioning moving picture data, the method comprisingoutputting a first-quantized signal by first-quantizing a received videosignal; partitioning the first-quantized signal into a preceding partand a succeeding part through a second quantization; and outputting anoutput signal generated as result of the second quantization as apartitioned stream signal. The partitioning step comprises re-quantizingthe first-quantized signal to generate a re-quantized signal;variable-length coding the re-quantized signal; inverse-quantizing there-quantized signal and calculating a difference based on thefirst-quantized signal; and variable-length coding the calculateddifference.

The re-quantized signal is an even-approximated coefficientcorresponding to the preceding part. The calculated difference is anodd-remainder coefficient corresponding to the succeeding part. A streamis constructed by inserting a texture marker for separating thepreceding part and the succeeding part.

In accordance with one embodiment, a method for partitioning movingpicture data, the method comprises generating a first-quantized signalby first-decoding a received stream; and restoring a video signal bysecond-decoding the first-quantized signal. The generating stepcomprises dividing the received stream into a preceding part and asucceeding part; variable-length decoding and inverse-quantizing thepreceding part; variable-length decoding the succeeding part; andoutputting the first-quantized signal by adding the preceding part tothe succeeding part. The preceding part is an even-approximatedcoefficient. The succeeding part is an odd-remainder coefficient.

In accordance with anther embodiment, a system for partitioning movingpicture data comprises a first inverse-quantizing mechanism forgenerating a first-quantized signal by first-quantizing a preceding partand a succeeding part of a data-partitioned stream; and a secondinverse-quantizing mechanism for outputting a video signal by performinginverse-quantization and inverse discrete cosine transform of the firstquantized signal.

The first inverse-quantizing unit comprises a divider for dividing thereceived data-partitioned stream into a preceding part and a succeedingpart; a first variable length decoder (VLD) for performingvariable-length decoding of the preceding part to generate a firstoutput signal; a first inverse-quantizer for inverse-quantizing thefirst output signal of the first VLD; a second VLD for performingvariable-length decoding of the succeeding part; and a first combinerfor outputting a first-quantized signal by combining an output signal ofthe first inverse-quantizer with an output signal of the second VLD.

An output signal of the first VLD is an even-approximated coefficient.An output signal of the second VLD is an odd-remainder coefficient. Insome embodiments, a method of partitioning a streaming data comprisesquantizing the streaming data to generate a first quantized signal;quantizing the first quantized signal to obtain an even-approximatedcoefficient; obtaining an odd-remainder coefficient; variable-lengthcoding the even-approximated coefficient and the odd-remaindercoefficient; and outputting a data-partitioned stream based on saidvariable length coding.

These and other embodiments of the present invention will also becomereadily apparent to those skilled in the art from the following detaileddescription of the embodiments having reference to the attached figures,the invention not being limited to any particular embodiments disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a block diagram illustrating an encoder used for a datapartitioning method in accordance with the related art;

FIG. 2 shows a bit string structure of the data partitioning method usedfor the MPEG-2 standard;

FIG. 3A shows a bit string structure of frames between screens of a datapartitioning method used for the MPEG-4 standard;

FIG. 3B shows a bit string structure of frames in a screen of the datapartitioning method used for the MPEG-4 standard;

FIG. 4 is a block diagram illustrating a structure of an encoder in anapparatus for partitioning moving picture data in accordance with oneembodiment the present invention;

FIG. 5 shows a method for partitioning data in accordance with oneembodiment of the present invention;

FIGS. 6A and 6B show a bit string structure of a method for partitioningdata in accordance with one embodiment of the present invention;

FIG. 7 is a block diagram illustrating a structure of an encoder of theapparatus for partitioning moving picture data in accordance with thepresent invention;

FIG. 8 is a flow chart illustrating a method for partitioning movingpicture data in encoding in accordance with one embodiment of thepresent invention; and

FIG. 9 is a flow chart illustrating a method for partitioning movingpicture data in decoding in accordance with one embodiment of thepresent invention.

Features, elements, and aspects of the invention that are referenced bythe same numerals in different figures represent the same, equivalent,or similar features, elements, or aspects in accordance with one or moreembodiments of the system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 4, a block diagram illustrating a structure of anencoder in an apparatus for partitioning moving picture data inaccordance with the present invention is provided. The encoder comprisesa first combining unit 11 for adding a received video signal to anoutput signal of a motion compensating unit 19; a DCT unit 12 forperforming DCT (discrete cosine transform) of the signal outputted fromthe first combining unit 11; a first quantizing unit 13 for quantizingthe signal of the DCT unit 12; a first inverse-quantizing unit 14 forinverse-quantizing the signal outputted from the first quantizing unit13; an IDCT (inverse discrete cosine transform) unit 15 for performingIDCT of the signal outputted from the first inverse-quantizing unit 14;a second combining unit 16 for combining the output signal of the IDCTunit 15 with the output signal of the motion compensating unit 19; aframe memory 17 for clipping and storing the signal outputted from thesecond combining unit 16; a motion judging unit 18 for estimating motionthrough the signal of the frame memory 17 and a received video signal; amotion compensating unit 19 for compensating motion by reflecting thejudged result of he motion judging unit 18 upon the signal stored in theframe memory 17; and a second quantizing unit 100 for outputting adata-partitioned stream by re-quantizing the output signal of the firstquantizing unit 13.

The second quantizing unit 100 comprises a second quantizer 101 forre-quantizing a signal outputted from the first quantizing unit 13; afist VLC (variable length coding) unit 102 for performing VLC (variablelength coding) of a signal ouptutted from the second quantizer 101; asecond inverse-quantizing unit 103 for inverse-quantizing a signaloutputted from the second quantizer 101; a third combining unit 104 forperforming subtraction operation of an output signal from the secondinverse-quantizing unit 103 and an output signal from the firstquantizing unit 13; a second VLC unit 105 for performing VLC (variablelength coding) of output signals of the third combining unit 104 and thesecond quantizer 101; and a data partitioning unit 106 fordata-partitioning output signals of the second VLC unit 105 and thefirst VLC unit 102 and outputting them.

The operation of the encoder of the moving picture data partitioningapparatus will be described. The encoder in accordance with oneembodiment of the present invention partitions a DCT coefficient into apreceding part as a priority part and a succeeding part as a lowerpriority part. The preceding part is a stream generated through thefirst quantizing unit 13 and the second quantizer 101, and thesucceeding part is a quantizing error signal as a difference between theoutput signal of the first quantizing unit 13 and the preceding partsignal. In more detail, the DCT coefficient is partitioned into y₁(k) asa stream generated by the second quantizer 101 and the succeeding partis a quantizing error signal as a difference between the output signalof the first quantizing unit 13 and the preceding part signal. In moredetail, the DCT coefficient is partitioned into y₁(k) as a streamgenerated by the second quantizer 101 and y₂(k) as a quantizing errorsignal between the y₁(k) and the output signal of the first quantizingunit 13.

When a quantizing interval of the second quantizer 101 is N, y₁(k) canbe defined as following. $\begin{matrix}{y_{1} = {{{sgn}\left( {x(k)} \right)}\left\lfloor \frac{{x(k)}}{N} \right\rfloor}} & \left( {{Equation}\quad 1} \right) \\{{{sgn}(x)} = \left\{ \begin{matrix}{1,} & {x \geq 0} \\{{- 1},} & {x < 0}\end{matrix} \right.} & \left( {{Equation}\quad 2} \right)\end{matrix}$  {circumflex over (x)}(k)=N y ₁(k),1≦k≦64  (Equation 3)y ₂(k)=x(k)−{circumflex over (x)}(k)=x(k)−N y ₁(k)  (Equation 4)

Herein, └x┘ is a maximum constant not greater than x, {circumflex over(x)}(k) is a reproduction value of the preceding part restored throughthe second quantizer 101, and y₂(k) is a coefficient of the succeedingpart.

Unlike the MPEG-2 or MPEG-4 data partitioning method, in the presentinvention, after making an approximate stream including high frequencycomponent through re-quantization of a signal, another stream isconstructed through a difference in value between the signal(approximate stream) and the signal before the re-quantization.

Herein, if the quantization interval N is defined as 2, the coefficienty₁(k) of the preceding part is an even-approximated coefficient of afirst-quantized signal (x(k)) outputted from the first quantizing unit13, and the coefficient y₂(k) of the succeeding part is an odd-remaindervalue generated by the even-approximation of the preceding part.

Referring to FIG. 5, a first-quantized signal (x(k)), a preceding partand a succeeding part partitioned by even-approximation are provided.Because the succeeding part coefficient is the odd-remainder of thefirst-quantized signal, they can be described as −1, 0, 1. Because anabsolute value of the succeeding part coefficient is binary numeral, itcan be described as a one-dimensional run-length code. In addition, codeof the succeeding part coefficient is same with that of the precedingpart coefficient. When the preceding part coefficient is 0 and thesucceeding part coefficient is not 0(y₁(k)=0,y₂(k)≠0), for example,additional code information as is inserted (e.g., at 1 bit).Accordingly, efficient encoding can be performed by reducing the bitnumber of the succeeding part.

Referring to FIGS. 6A and 6B bit string structures of a datapartitioning method in accordance with the present invention areprovided. As depicted in FIG. 6A, by fragmenting the DCT coefficientinto a preceding part and a succeeding part with a texture marker,frames between screens are partitioned into three regions (partition 0,partition 1, partition 2 ). In a frame in the screen as shown in FIG.6B, it is partitioned into an even-approximation part (preceding part)and a rest part (succeeding part), the preceding part is partitionedinto a DC coefficient and an AC coefficient. The even-approximated DCcoefficient and a macro block header construct a partition 0, theeven-approximated AC coefficient is related to a partition 1, andaccordingly it is generally partitioned into three regions.

In addition, not the original DC coefficient but the even-approximatedDC coefficient is placed in the partition 0 of the frame in the screen,it is possible to reduce information loss probability in the partition0. In information loss occurrence due to a transmission error, wheninformation loss occurs in the partition 0, all data have to bedisregarded, and accordingly it is fatal in most.

Referring to FIG. 7, a structure of a decoder used for the datapartitioning method is provided. As shown, the decoder comprises apartitioning unit 201 for receiving an encoded bit stream andpartitioning it into a preceding part and a succeeding part; a first VLD(variable length decoding) unit for performing VLD of the preceding partof an output signal of the partitioning unit 201 and outputting aneven-approximation coefficient; a first inverse-quantizing unit 203 forinverse-quantizing the even-approximate coefficient outputted from thefirst VLD unit 202 and outputting a preceding part reproduction value; asecond VLD unit 204 for performing VLD of the succeeding part of theoutput signal of the partitioning unit 201 and outputting anodd-remaining coefficient; and a first combining unit 205 for combiningthe odd-remaining coefficient with the preceding part reproductionvalue.

In some embodiments, a second inverse-quantizing unit 206 forinverse-quantizing the output signal of the first combining unit 205; anIDCT (inverse discrete cosine transform) unit 207 for performing IDCT ofthe output signal of the second inverse-quantizing unit 206; a motioncompensating unit 208 for performing motion compensation by using theoutput signal of the first VLD unit 202 and the signal stored in theframe memory 210; a second combining unit 209 for combining the outputsignal of the motion compensating unit 208 with the output signal of theIDCT unit 207 and outputting a motion-compensated video signal; and aframe memory 210 for storing the signal of the second combining unit 209are included.

The operation of the decoder of the moving picture data partitioningapparatus in accordance with the present invention will be described.The decoder partitions an inputted bit stream into each partitiondivided by a marker. y₁(k), as a preceding part, is decoded according toa defined coding table and is doubled in the first inverse-quantizingunit 203. The succeeding part as the odd-remaining coefficient of theeven-approximated coefficient is decoded in the second VLD unit 204. Indecoding of a run-length of 0 in the succeeding part, additional 1 bitshowing code information of the odd-remaining coefficient is decodedonly when the even-approximated coefficient is 0. In cases except that,a code of the odd-remaining coefficient is determined as the same codewith the odd-approximated coefficient.

A first-quantized coefficient x(k) can be reconstructed by adding theoutput signal of the first inverse-quantizing unit 203 to the outputsignal of the second VLD unit 204. In accordance to one embodimentEquation 5 provides: $\begin{matrix}\begin{matrix}{{x(k)} = {{\hat{x}(k)} + {y_{2}(k)}}} \\{{= {{2{y_{1}(k)}} + {y_{2}(k)}}},{1 \leq k \leq 64}}\end{matrix} & \left( {{Equation}\quad 5} \right)\end{matrix}$

The first-quantized coefficient is added to the signalmotion-compensated through the second inverse-quantizing unit 206 andthe IDCT unit 207 and is outputted as a decoded video signal. In thedecoder in accordance with the present invention, when a transmissionerror occurs, decoding is performed in order from a preceding part inwhich loss does not occur, if the preceding part is lost, part lowerthan the preceding part is disregarded. In more detail, when loss occursin the partition 2 by a transmission error, decoding is performedthrough the partitions 0 and 1. When loss occurs in the partition 1,lost macro block is reconstructed through information in the partition0. And, when loss occurs in the partition 0, the decoder disregards allinformation.

Referring to FIG. 8, a data partitioning method in encoding is provided.A received video signal is first-quantized at step S11. Thefirst-quantized signal is outputted. The first-quantized signal issecond-quantized, at step S12. Herein, by using 2 as a second quantizinginterval, a second quantized output signal is an even-approximatedcoefficient about the first-quantized signal. The even-approximatedcoefficient is an approximate stream including all frequency componentsfrom a low frequency component as the preceding part and a highfrequency part as the succeeding part.

By using the difference between the first-quantized signal and theeven-approximated coefficient, an odd-remaining coefficient iscalculated as shown at step S13. Herein, the odd-remaining coefficientis corresponded to the succeeding part, absolute value thereof can bedescribed as 0 and 1. Because it has the same code with that of theeven-approximated coefficient, when the even-approximated coefficient is0, for example, and the odd-remaining coefficient is not 0, codeinformation as additional is inserted in order to describe a sign at 1bit.

For example, a first-quantized signal is { . . . −6, −5, −4, −3, −2, −1,0, 1, 2, 3, 4, 5, 6 . . . }, even-approximated coefficient is { . . .−3, −2, −2, −1, −1, 0, 0, 0, 1, 1, 2, 2, 3 . . . }, and odd-remaindercoefficient is { . . . 0, −1, 0, −1, 0, −1, 0, 1, 0, 1, 0, 1, 0 . . . }.And, because even-approximated coefficient of the first quantized signal{−1, 1} is {0, 0}, a code bit for respectively showing {−1, 1} isinserted into the odd-remainder coefficient.

By performing the variable-length coding of the even-approximatedcoefficient and the odd-remainder coefficient respectively as shown atstep S14, a signal is outputted from the data partitioning unit as apartitioned stream as shown at step S15. Referring to FIG. 9, a datapartitioning method in decoding will be described. By receiving thedata-partitioned stream signal through the encoder and partitioningdata, at step S21 and performing VLD (variable-length coding) of thedata, at step S22, an even-approximated coefficient and an odd-remaindercoefficient are obtained, at step S23. The even-approximated coefficientis inverse-quantized about the second quantizing in the encodingprocess. The even-approximated coefficient is added to the odd-remaindercoefficient and is outputted as a first-quantized signal.

For example, when the even-approximated coefficient is { . . . −3, −2,−2, −1, −1, 0, 0, 0, 1, 1, 2, 2, 3 . . . }, the odd-remaindercoefficient is { . . . 0, −1, 0, −1, 0, −1, 0, 1, 0, 1, 0, 1, 0 . . . },a second-quantizing interval in the encoding process is 2, theeven-approximated coefficient through the inverse-quantizing isoutputted as { . . . −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6 . . .}, and a signal same with the first-quantized signal in the encodingprocess is outputted. In the first-quantized signal, inverse-quantizingabout the first quantizing in the encoding process is performed at stepS24. Motion compensation about the signal is performed, and accordinglya video signal is obtained as shown at step S25.

The apparatus and method for partitioning moving picture data inaccordance with the present invention can be efficiently used for notonly a radio terminal using a radio communication network but also errorimpurity transmission of moving picture information in a wirecommunication network. And, it can be applied to not only moving picturetransmission such as a MPEG-2, a MPEG-4 and a H.263, etc. but also stillpicture transmission such as a JPEG (joint photographic coding expertgroup), etc. The present invention can be efficiently applied to errorimpurity transmission of all multimedia information encoded by using aDCT in a wire/wireless communication network.

As described above, in the apparatus and method for partitioning movingpicture data in accordance with the present invention, by including allfrequency components from a low frequency part to a high frequency part,reproduction picture quality can be improved in comparison with theconventional art decoding only a specific part.

In addition, in the apparatus and method for partitioning moving picturedata in accordance with the present invention, by dividing a DCTcoefficient into an even-approximated coefficient and an odd-remaindercoefficient through re-quantization and respectively allocating them toa preceding part and a succeeding part, it is possible to decrease alength of a code word and reduce loss probability at the preceding part.Thus, in accordance with one embodiment of the present invention, bydecreasing code information at a succeeding part, it is possible toperform efficient encoding.

1. An apparatus for partitioning moving picture data, comprising: afirst quantizing unit for first-quantizing a received video signal andoutputting a first-quantized signal; a second quantizing unit forsecond-quantizing the first-quantized signal to produce a re-quantizedsignal, partitioning the first-quantized signal into a preceding partand a succeeding part and outputting a partitioned stream signal,wherein the preceding part is generated by an inverse quantizing unitthat inverse-quantizes the re-quantized signal and a difference signalis generated between the first-quantized signal and the preceding part;a first variable length coding unit for coding the re-quantized signal;and a second variable length coding unit for coding the differencesignal.
 2. The apparatus of claim 1, wherein the preceding part and thesucceeding part comprise at least one frequency component.
 3. Anapparatus for partitioning moving picture data comprising: a firstquantizing unit for first-quantizing a received video signal andoutputting a first-quantized signal; the first quantizing unitcomprising a first quantizer for quantizing the received video signal,and a second quantizing unit for second-quantizing the first-quantizedsignal and partitioning the first-quantized signal into a preceding partand a succeeding part, wherein the second quantizing unit comprises: asecond quantizer for re-quantizing the first-quantized signal togenerate an output signal; a first variable length coder (VLC) forvariable-length coding the output signal generated by the secondquantizer; a second inverse-quantizer for inverse-quantizing the outputsignal generated by the second quantizer; a combiner for performingsubtraction operation of output signals generated by the first quantizerand the second-inverse quantizer; a second VLC for variable-lengthcoding output signals generated by the third combiner and the secondquantizer; and a data partitioner for outputting output signalsgenerated by the second VLC and the first VLC.
 4. The apparatus of claim3, wherein the second quantizer outputs an even-approximated coefficientas the preceding part by having a quantization interval set to apredetermined value.
 5. The apparatus of claim 3, wherein an outputsignal of the third combiner is an odd-remainder coefficient as thesucceeding part equal to a predetermined value.
 6. The apparatus ofclaim 5, wherein the odd-remainder coefficient comprises codeinformation when the odd-remainder coefficient is equal to a first valueand a pertinent even-approximated coefficient is not equal to a secondvalue.
 7. The apparatus of claim 6, wherein the first value isapproximately
 1. 8. The apparatus of claim 6, wherein the second valueis approximately
 0. 9. The apparatus of claim 5, wherein theodd-remainder coefficient as the succeeding part is equal toapproximately
 0. 10. The apparatus of claim 5, wherein the odd-remaindercoefficient as the succeeding part is equal to approximately
 1. 11. Anapparatus for partitioning moving picture data comprising: a coding unitfor outputting a stream comprising a DCT coefficient divided into aneven-approximated coefficient and an odd-remainder coefficient byfirst-quantizing a received video and second-quantizing afirst-quantized signal; a decoding unit for obtaining a first-quantizedsignal by performing inverse-quantization about the stream generated bythe coding unit and obtaining a restored video signal by performinginverse-quantization about the first-quantizing; an inverse-quantizingunit for inverse-quantizing the re-quantized signal and calculating adifference signal based on the first-quantized signal; and avariable-length coding unit for coding the re-quantized signal and thedifference signal.
 12. An apparatus for partitioning moving picture datacomprising: a coding unit for outputting a stream comprising a DCTcoefficient divided into an even-approximated coefficient and anodd-remainder coefficient by first-quantizing a received video andsecond-quantizing a first-quantized signal; and a decoding unit forobtaining a first-quantized signal by performing inverse-quantizationabout the stream generated by the coding unit and obtaining a restoredvideo signal by performing inverse-quantization about thefirst-quantizing, wherein the coding unit comprises: a first quantizerfor outputting a first-quantized signal by first-quantizing a receivedvideo signal; a second quantizer for outputting an even-approximatedcoefficient by re-quantizing the first-quantized signal; a first VLC(variable length coder) for variable-length coding an output signal ofthe second quantizer; an inverse-quantizer for inverse-quantizing anoutput signal of the second quantizer; a combiner for outputting anodd-remainder coefficient by performing subtraction operation of outputsignals of the second inverse-quantizer and the first quantizer; asecond VLC (variable length coder) for variable-length coding outputsignals of the combiner and the second quantizer; and a data partitionerfor outputting output signals of the second VLC and the first VLC as adata-partitioned stream.
 13. The apparatus of claim 12, wherein anoutput signal of the combiner is an odd-remainder coefficient.
 14. Theapparatus of claim 13, wherein the odd-remainder coefficient comprisescode information when it is equal to a first value and a pertinenteven-approximated coefficient is not equal to a second value.
 15. Theapparatus of claim 12, wherein the decoding unit comprises: a dividerfor dividing the data-partitioned stream into a preceding part and asucceeding part; a first VLD (variable length decoder) for outputting aneven-approximated coefficient by variable-length decoding the precedingpart; a first inverse-quantizer for inverse-quantizing an output signalof the first VLD; a second VLD (variable length decoder) forvariable-length decoding the succeeding part; a first combiner foroutputting a first-quantized signal by combining an output signal of thefirst inverse-quantizer with an output signal of the second VLD; and asecond inverse-quantizer for outputting a video signal by performinginverse-quantization and inverse discrete cosine transform of the firstquantized signal.
 16. A method of partitioning a streaming data, themethod comprising: quantizing the streaming data to generate a firstquantized signal; quantizing the first quantized signal to obtain aneven-approximated coefficient; obtaining an odd-remainder coefficient;variable-length coding the even-approximated coefficient and theodd-remainder coefficient; and outputting a data-partitioned streambased on said variable length coding; partitioning the data-partitionedstream into a plurality of data streams; variable-length coding therespective data streams; obtaining an even-approximated coefficient andan odd-remainder coefficient through second-inverse quantization tooutput a restored video signal, based on a first quantization;calculating a difference signal based on the first-quantized signal; andvariable-length coding the calculated difference.
 17. A method forpartitioning moving picture data, the method comprising: outputting afirst-quantized signal by first-quantizing a received video signal;partitioning the first-quantized signal into a preceding part and asucceeding part through a second quantization; and outputting an outputsignal generated as result of the second quantization as a partitionedstream signal, wherein partitioning comprises: re-quantizing thefirst-quantized signal to generate a re-quantized signal;variable-length coding the re-quantized signal; inverse-quantizing there-quantized signal and calculating a difference based on thefirst-quantized signal; and variable-length coding the calculateddifference.
 18. The method of claim 17, wherein the re-quantized signalis an even-approximated coefficient corresponding to the preceding part.19. The method of claim 17, wherein the calculated difference is anodd-remainder coefficient corresponding to the succeeding part.
 20. Themethod of claim 17, wherein a stream is constructed by inserting atexture marker for separating the preceding part and the succeedingpart.